Nitrocellulose Membrane
Definition
The porous polymer strip along which sample fluid wicks by capillary action. The test and control line antibodies are immobilised directly on the nitrocellulose. Its pore size controls flow rate and background signal.
- Function
- Porous strip along which sample wicks by capillary action
- Carries
- Immobilised test and control line antibodies
- Controls
- Flow rate and background signal via pore size
Common questions
What happens if the membrane's pore size is wrong for the sample?+
Too fine a pore size slows flow and can trap particulates, weakening or delaying line development. Too coarse a pore size lets sample pass too quickly for antibody binding to occur, producing a faint or false-negative result.
Does the nitrocellulose itself react with the target analyte?+
No, the membrane is an inert wicking substrate. The antibodies immobilised on it at the test and control lines are what bind the target, so a properly stored membrane does not degrade the assay's specificity.
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